Cleaning cards for cleaning a variety of internal surfaces of machine components are well known in the art. Such cleaning cards have been employed to clean internal machine-actuating mechanisms of the type intended to receive an operating card or other machine-operating substrate (e.g., paper currency) for actuating the operation of a machine.
The most common commercially available cleaning cards are substantially flat substrates that are intended to closely approximate the dimensions of the machine-operating substrate (e.g., credit card, paper currency, pass including magnetic stripe for actuating subway turnstiles, hotel door locks, etc.) so that they can be received in the same slot as the machine-operating substrate for the purpose of cleaning internal machine components. However, in a number of machine-operating devices internal surfaces to be cleaned are spaced further apart than the maximum thickness of a cleaning card adapted to be received in the device. To deal with this problem cleaning cards have been designed with collapsible, raised surfaces for cleaning or removing foreign objects from such internal surfaces, as is exemplified by the disclosures in U.S. Pat. Nos. 6,243,908 (Battle, et al.), 6,107,221 (Nakajima, et al.) and 5,153,964 (Gelardi, et al.). A discussion of these latter three (3) patents is included in application Ser. No. 10/857,382, now pending, the subject matter of which is fully incorporated herein by reference. For purposes of brevity, a discussion of the above-three prior art patents will not be repeated herein.
Suffice it to state that the prior art cleaning card structures, while generally usable for their intended purpose, are not capable of effectively cleaning out certain types of dust particles (e.g., paper dust) that tend to collect, or build up adjacent the trailing edge of closely spaced apart machine components, such as the trailing edges of a thermal printing head and an aligned support platen in thermal printers. Moreover, in thermal printing devices it is not uncommon for debris to actually become burnt onto the print head, due to the inclusion of pressure-sensitive adhesives that commonly are employed in the paper substrates directed through the printing devices. Such burnt-on debris is not consistently removed in an effective manner with the use of conventional cleaning card structures.
In view of the deficiencies in prior art cleaning card structures a need exists for a cleaning card that is capable of effectively and consistently removing paper dust and other debris that tend to build up adjacent trailing edges of closely spaced apart machine components, such as the trailing edges of a thermal print head and an aligned, closely spaced-apart support platen through which paper labels to be printed are directed. In addition, a need exists for an improved cleaning card that also is capable of effectively and consistently removing debris that is burnt onto heated internal components, such as the thermal print head of a thermal printing unit. It is to such improved cleaning card constructions that the present invention is directed.